Internal illumination of household appliances, such as, for example refrigerators, by means of light bulbs disposed within light-bulb holders the only function of which is to support the light bulb and which thus require, during installation upon the household appliance, a set of other accessories, such as, for example a door-switch for switching off the light when the refrigerator door is closed, are of course known; and while this type of light-bulb holder has a low cost and occupies little space it requires complex assembly and cabling procedures because it must be functionally and electrically connected to the accessories.
Built-in light-bulb holders which incorporate a door switch and perform additional functions, such as, for example, providing a support for thermostats and terminal boards, are also known. These built-in light-bulb holders have a high cost and/or are too complex for use upon basic household appliances.